Image
quality is decreased substantially in 7T high resolution T2*-weighted images
in Alzheimers disease (AD) patients compared to younger volunteers. The
source of the image artifacts was investigated in phantom experiments using
translational/rotational motion parameters and f0 fluctuations from AD
patients. It was found that image degradation by f0 fluctuations was a
factor-of-four times larger than artifacts caused by movement typical of AD
patients. By implementing a navigator echo correction for f0 fluctuations,
the image quality increased considerably. This technique was succesfully
applied in four AD patients showing significant image quality improvements.